Sustainable plant-based ingredients as wheat flour substitutes in bread making

Bread as a staple food has been predominantly prepared from refined wheat flour. The world’s demand for food is rising with increased bread consumption in developing countries where climate conditions are unsuitable for wheat cultivation. This reliance on wheat increases the vulnerability to wheat supply shocks caused by force majeure or man-made events, in addition to negative environmental and health consequences. In this review, we discuss the contribution to the sustainability of food systems by partially replacing wheat flour with various types of plant ingredients in bread making, also known as composite bread. The sustainable sources of non-wheat flours, their example use in bread making and potential health and nutritional benefits are summarized. Non-wheat flours pose techno-functional challenges due to significantly different properties of their proteins compared to wheat gluten, and they often contain off-favor compounds that altogether limit the consumer acceptability of final bread products. Therefore, we detail recent advances in processing strategies to improve the sensory and nutritional profiles of composite bread. A special focus is laid on fermentation, for its accessibility and versatility to apply to different ingredients and scenarios. Finally, we outline research needs that require the synergism between sustainability science, human nutrition, microbiomics and food science.


Influences on dough properties
Influences on sensory and nutritional attributes of bread References Legume-based Chickpea Flour 5−30% -Increased water absorption and dough development time.
-Decreased dough extensibility and resistance to deformation.
-Above 10% replacement leading to sticky dough, higher onset and peak gelatinization temperatures, and higher elastic and loss moduli.
-Increased protein digestibility and improved amino acid profiles compared to wheat control.
-Above 10% substitution leading to reduced specific volume and increased hardness, higher densities, and darker crumb.
-Decreased bread specific volume and denser crumb structure.
-Increased contents of lysine-rich proteins, dietary fiber, and phenolic compounds.
-Enhanced antioxidant potential compared to wheat control.
-Above 10% substitution reducing specific volume with increased density.
-Aroma profile and specific volume improved and crumb hardness decreased by fermentation with in situ dextran production. -Reduced loaf specific volume and increased crumb hardness.
-Improved specific volume and softness, and nutritional quality (free amino acids and protein digestibility) by fermentation with in situ dextran production compared to wheat control.
-Decreased the dough stability and elasticity.
-Increased dietary fiber content, total phenolic compounds, and antioxidant activity.
-Reduced specific volume and increased crumb hardness.
-Improved bread texture quality and sensory properties i.e., reduced off-flavors such as bitter taste and aftertaste by fermentation with in situ dextran production. Tef Flour 10−40% -Tef addition resulting in higher levels of extractable polyphenols and anti-radical activity.
-Above 30% replacement leading to a decrease in specific volume and increase in crumb hardness.
-Lower bread volume, firmer crumb and altered crumb pore structure.
-Improved texture with acceptable quality for as high as 50% replacement by adding emulsifier (DATEM and distilled monoglycerides) and enzymes (xylanase and transglutaminase).
-Increased contents of fiber and β-glucan.
-Lower loaf specific volume and negative textural properties above 30% addition.
-Reduced dough stability, maximum resistance to extension, dough extensibility, and energy value.
-Increased contents of dietary fiber, the phenolic content, and antioxidant activity.
-Content and Mw of oat β-glucan unaffected by fermentation.
-Bread volume and crumb properties mainly affected by gluten and water contents.

Flander et al. 2007, 2011
Oat Soluble fiber 10−14% -Lower specific volume and porosity, darker color, higher hardness, and lower springiness and cohesiveness compared to wheat control.
-The negative effects effectively counteracted by optimizing the water content in bread formulas.
-Gluten secondary structure changed and gluten network diisrupted.
-Above 10% addition resulting in smaller specific volume, increased crumb hardness and coarse porosity.
-Higher antioxidant activity and reduced in vitro starch digestibility with lower estimated glycemic index due to higher contents of slowly digestible starch and resistant starch.
-Chemical, textural, and sensory features improved by fermentation. -Decreased specific volume and increased hardness.
-Improved specific volume and softness and increased microbial safety by fermentation with exopolysaccharide production.
-Enzymatic hydrolysis of starch in surplus bread hydrolysate with high-malto-oligosaccharides resulting in increased specific volume and reduced crumb hardness and staling rate compared to non-treated control.
-Increased volume, preferrable aroma and taste traits and overall quality by fermentation of BSG (up to 10%).
-Adding fermented BSG at above 10% leading to reduced taste quality.
-Enzyme treatment leading to larger specific volume and softer crumb than extrusion treatment. Plessas et al. 2007Steinmacher et al. 2012Vriesekoop et al. 2021